SETSYS fast-path for DFSMShsm functions

DFSMShsm performs two main functions: availability management and space management. Availability management is used to make data available by automatically copying new and changed data sets to backup volumes and DASD volumes to dump tapes. Space management is used to manage DASD space by enabling inactive data sets to be moved off fast-access storage devices thus creating free space for new allocations. DFSMShsm also provides other supporting functions that are essential to your installation's DFSMShsm environment.

The following table illustrates the functions performed by DFSMShsm for availability management, space management and these supporting functions.

The SETSYS command and its parameters are used to establish a DFSMShsm environment. When DFSMShsm is installed, a default set of SETSYS parameters is used. You can specify one or more SETSYS commands in the ARCCMDxx PARMLIB member that is used during the startup of DFSMShsm or you can issue SETSYS commands with specific parameter values after DFSMShsm is started.

The following table lists both the main and supporting functions performed by DFSMShsm and the SETSYS parameters that affect them. The left column lists the functions and the right column lists the SETSYS parameters that affect these functions. This table emphasizes SMS-managed user data and it excludes parameters that relate to non-SMS user data and backup to DASD. Refer to the SETSYS examples at the end of this SETSYS topic for common user scenarios that you can use for your installation.